品级Grade                               指示剂级（IND)  
                                    (indicator (pH 4.2-6.2))
外观Appearance                          红棕色粉末
红外光谱鉴别Infrared spectrometry       Conforms
水溶解试验solubility in water           clear(0.1% in water)
pH变色域visual transition interval      pH 4.2 (red) to pH 6.2 (yellow)

品级Grade                                ACS级  
                                     (ACS reagent, 95 %)
外观Appearance                          红棕色粉末
红外光谱鉴别Infrared spectrometry       Conforms
染料含量Dye content,                    95%  
水溶解试验solubility in water           clear(0.1% in water)
pH变色域visual transition interval      pH 4.2 (red) to pH 6.2 (yellow)
λ                                       430 - 440 nm
                                        c = 0.01 g/l; Water
消光系数Extinction Coefficient          ≥17000
λ                                       256 - 260 nm
消光系数Extinction Coefficient          ≥8000
Visual Transition Interval              pH 4.2  Pink
Visual Transition Interval              pH 5.5  Orange
Visual Transition Interval              pH 6.2  Yellow
pH变色域visual transition interval      pH 4.2 (red) to pH 6.2 (yellow)